…the same empirical specification used in previous studies (ie. logistic regression of own health ~ friends’ health + X) also “detects” significant and fairly large network effects for implausible outcomes such as acne, height, and headaches. For example, having a friend with headache problems increases the respondent’s chances of headache problems by about 47% on average. These implausible placebo findings suggest that previous findings may have been driven by confounding.

This study, which they are calling a “placebo” study essentially proves that there is an inherent bias in the way the other studies were conducted. The correlation between people who associate with each other is not proof that it causes them to get fat, or be smokers, etc.

Funny, I haven’t seen much press on this study, have you? So much for the Tall-isity Epidemic.

Now this is funny. Also, occurs to me – did the researchers correct for genetics? Ie., if a person is tall, or fat, or has acne, there’s a fair chance that a lot of people around them will also show those physical characteristics because they’re, you know, related?

Also there’s the issue of affinity, birds of a feather etc. I have a higher than average percentage of friends who’re nuts about music or who play instruments. And hey, that MAY have something to do with my being a music journalist. Or, you know, it could show something about how liking music is contagious.

I really wish someone would familiarise journalists who report science stories (and some scientists) with the principle of Occam’s Razor.

Like, I can tell you one reason that people with acne might spend a lot of time with other people with acne. Most of them are teenagers. Teenagers hang out with other teenagers. This is not actually rocket science.